


Jutsu Gone Wrong

by zombie_honeymoon



Category: Naruto
Genre: Age Regression/De-Aging, Alternate Universe - Canon Divergence, Found Family, Gen, M/M, OOC
Language: English
Status: Completed
Published: 2020-08-21
Updated: 2020-08-21
Packaged: 2021-03-07 01:49:35
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 2,564
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26029000
Author URL: https://archiveofourown.org/users/zombie_honeymoon/pseuds/zombie_honeymoon
Summary: Kakuzu and Hidan return from a mission that went all wrong and Hidan is no longer himself.
Relationships: Hoshigaki Kisame/Uchiha Itachi
Comments: 6
Kudos: 87
Collections: Writer's Month 2020





	1. One

**Author's Note:**

> Writer's Mont Day 19 - Deaging 
> 
> Not a fan of this trope, but I do want to try to complete all the prompts and I'm so close so I did a little something for it. I'm not all that happy with this and kind of embarrassed to post it but not everything has to be perfect, it's just a silly little fic for fun. Are they ooc? Yes. I did try to not let it get too overly ooc and absurd, but I'm sure they still are. Chapter two will hopefully be up later this afternoon!  
> Enjoy!  
> Want to find me on tumblr? I'm @zombie-honeymoon, stop by and say hi if you'd like.

Just as Kisame was about to go start something for dinner, the clatter of metal, recognized by both Kisame and Itachi as Hidan’s scythe being tossed on the floor, followed by Kakuzu’s rasied voice had them both sighing. The zombies were back, meaning any relative peace and quiet was gone. He went out anyways only to find Kakuzu going through the refrigerator while a child, soaked from the rain and wearing what appeared to be nothing but an oversized t-shirt sat at the table.

“Uh, Kakuzu? Why is there a kid in here?” 

As he got closer, he thought the kid looked an awful lot like Hidan. Same hair, same eyes. Only much younger. If Kisame had to guess, the kid was four, maybe five. 

“I need to see Konan. Where is she?” Kakuzu demanded, ignoring Kisame’s question completely as he set a plate of week old chicken in front of the boy, “Eat.”

“Up in the office most likely. Kakuzu, did Hidan have a kid with someone and you two got stuck with him?” He swiped the plate away from the table just as a tiny hand was reaching for the chicken, “You don’t want to eat that, should’ve been thrown out by now. Kakuzu, you’re going to give the poor kid food poisoning.”

“He’d be fine.” Kakuzu grumbled, glaring at the boy as if hoping he might burst in the flames on the spot, and then he was gone.

Irritated, Kisame watched Kakuzu leave before slowly turning his attention back to the kid, “Hey, so what’s up? You got a name?”

The boy just looked at him before mumbling, his voice pitched high, “Shut the fuck up,” as he buried his face in his arms on the table.

“You’re definitely Hidan’s kid.” Kisame sighed, “You hungry?”

The boy ignored him and Kisame felt bad for him, obviously he was hungry if he was going to eat old chicken. Where the hell was Hidan? No wonder Kakuzu was in a pissy mood, left with a kid and the parent nowhere in sight. The fact Hidan had a kid at all had likely put him in a mood to begin with… Kisame wasn’t entirely sure just what their relationship was, but he knew Hidan didn’t look at anyone the way he looked at Kakuzu, and vice versa. 

Moments later Itachi walked in, pausing when he saw the boy.

“Hidan’s kid.” Kisame said as explanation, “Don’t ask, I don’t know anything about it.”

The boy lifted his head, magenta eyes narrowed at Kisame and Itachi watched him closely, taking a seat opposite him as Kisame started some rice.

“This had better not be a joke.” Konan’s voice came from somewhere down the hallway.

“Don’t be ridiculous, Konan, since when do you know Kakuzu as the joking type?” Pein’s voice followed.

Itachi hadn’t taken his eyes off the kid, who was actively avoiding his gaze, while Kisame had started making some soup. Miso, and a side of rice, he figured the kid would eat it and it would be quick to make.

Konan, Pein and Kakuzu came to stand in the kitchen, surrounding the boy, “Impossible.” Konan shook her head.

“Well, what do we do with him?” Kakuzu grumbled.

“I was making some dinner.” Kisame said, “He’s hungry. Then Hidan can give his kid a bath. Where the hell is he anyways?” 

“Kisame… that’s not Hidan’s kid.” Itachi said, moving to stand against the counter as Kisame stirred the pot of soup.

Kakuzu pointed at the boy, shouting, “ _That_ is Hidan!”

“What?” Kisame looked up from the stove, dropping the spoon he was stirring the soup with into the pot, cursing softly.

Kakuzu pulled a chair out and sat heavily, “Our mission took us into the Land of Snow. Someone had stolen a forbidden jutsu and it was used on this _complete_ _idiot_ who went rushing in to start his damn ritual before I could stop him!” 

Hidan looked away as everyone kept staring at him, his lip quivering and eyes filled with tears. He wiped at them but the tears kept coming. 

“Don’t you dare start crying!” Kakuzu growled, “It’s your own damn fault!” That was _not_ an actual child, it was Hidan! He was not going to feel bad for making him cry, _again,_ but when he started sniffling and his shoulder shook, Kakuzu got up and left the room. 

“F--fuck you, Kakuzu…” Hidan mumbled as he tried to stop crying. He couldn’t help it, no matter how hard he tried, he just couldn’t control his emotions, and on top of that he was exhausted, sore and hungry, and everyone was looking at him! 

Konan rolled her eyes and bit her lip to keep from laughing, she knew she was awful for wanting to laugh but the whole situation was just too comical to her. Hidan was now an actual toddler. How fitting, she thought.

“Itachi, you had a little brother, I’m assigning you and Kisame to take care of him.” Pein said as he started to leave to go after Kakuzu.

“No.”

Pein slowly raised a single brow at Kisame's repsonse, “No? You don't get to say no.” 

“Kakuzu should take care of him. That’s his partner.” Kisame replied as he ladled soup into bowls for himself, Itachi and Hidan. Then scooped some rice onto three small plates. If anyone else wanted any, they could serve themselves with what was left.

“He won’t be able to, he’s leaving in the morning to find a way to undo this jutsu, Hidan is staying here. Konan will be going with him.” Explained Pein, “So from now until they get back, Hidan is your responsibility. Make sure he doesn't climb a bookcase and get crushed under it, or drown in the bathtub. He's still a member of this organization.” He motioned for Konan to follow him and they left to go after Kakuzu and explain the new mission.

“Great… just what I always wanted a kid who could actually murder me.” Kisame rolled his eyes as he set the food in front of Hidan, “There’s a reason they always use kids in horror films. And let’s not forget that this one worships an actual god of death.” 

“It won’t be that bad. If he really wanted to kill us he would have tried by now and he hasn't.” Itachi told him, “Hidan, eat. Then you can have a bath and get some dry clothes on and go to bed.” 

Hidan turned his head towards Itachi, and took a deep breath. He looked like he wanted to say something but was too tired to argue and instead reached for the rice with a tiny hand. 


	2. Two

**Summary for the Chapter:**

> Sometimes a family can be two missing nin who were forced to kill their teammates and family and a twenty two year old missing nin stuck in the body of a five year old.

**Notes for the Chapter:**

> Writer's Month Day 21 - Family
> 
> Please enjoy the follow up and conclusion of the deaging fic. I can't believe I wrote this ridiculousness but I hope it's enjoyable at least. Again, yes, they are OOC. You know, I would consider this whole fic to be like a 'writing dump' similar to a sketch dump but it's writing. It's barely edited, barely proofread, I bet there's mistakes and I'm sorry but I am tired and melting in this heat and just going to post this second chapter and get back to work.   
> Thanks for reading!

The following day Kisame went out to buy a few sets of clothes for Hidan and something for him to sleep in while Itachi kept an eye on him at the base. If anyone thought it odd that an Akatsuki member was buying children's clothes, they didn’t say anything. As he was leaving the store, something caught his eye and with a mischievous look, Kisame went back inside to buy it. Oh, Hidan was going to _hate_ it!

Once back, Kisame dumped out the clothes onto the couch next to where Hidan was sitting. Something brightly colored fell out between the clothes, catching his eye.

“What’s that?” Hidan asked, reaching into the pile of clothes to pull out a bright pink plastic cup with a spout on the lid and as he held it up, turning it over in his little hands, his frown increasingly deeper as it dawned on him what it was.

“It’s a sippy cup, so you don’t spill!” Kisame laughed until his eyes watered and he couldn’t breathe, the look of absolute indignation mixed with rage on Hidan’s face was too much for him to handle. 

“I’m gonna sacrifice you to Jashin-sama!” Hidan threw the cup across the room as he glared up at Kisame.

“No one is sacrificing anyone.” Itachi said as he came into the room at the sound of commotion, “Hidan, behave or I will put you in a time out, and you’re not going to like the time out I put you in. Kisame, don’t incite him.” 

That seemed to do the trick for Hidan and he settled down out of fear of being trapped in a genjutsu as a time out. Until he looked through the clothes and saw the footed shark onesie pajama Kisame bought him. 

“What the fuck?! I’m not wearing this!” He screeched and then lunged for Kisame, grabbing hold of his arm and sinking his sharp little toddler teeth deep into his flesh. 

* * *

After a few days, they fell into a routine watching over Hidan who seemed to try to get into trouble no matter what he did. At one point, Itachi was sure he was intentionally trying to drive them up the wall, but it was hard to tell. Hidan seemed to have more energy as a child than he had as an adult, or he just controlled himself better as an adult. They started taking him out for training, to keep up his skills and release his energy. It seemed to help for the most part.

At night they found Hidan slept lightly, and often woke from nightmares. When asked, he refused to say anything about them, but after a several nights he ended up sleeping in the room with Kisame and Itachi.

Kisame set up a futon on the floor for Hidan but eventually he joined them in their bed, uninvited, pushing his way between them. It was sometimes easy for them to forget he wasn’t an actual five year old, but in the dark, the fearful eyes of a child were what they saw and took pity on. 

* * *

“How do you think this works?” Kisame asked, with Hidan sitting on his shoulders as they walked back to the base, tired out after some training, “Do you think his mind is also the mind of a five year old, like his body, or would that have stayed intact?”

“I think…” Itachi began, thoughtful, “that like his body, his mind has the limits of whatever age the jutsu made him. It explains the crying and emotional outbursts, like how he tires so easily. It may also explain his nightmares. All of Hidan’s memories and knowledge seem to have remained, but his mind seems to struggle with processing those things. A five year old would find the things he’s done terrifying.”  
  
“I think a five year old would find the things all of us have done to be terrifying.” Kisame said, his voice low. 

“I’m hungry.” Hidan whined, tugging on Kisame’s hair with grubby little hands to get his attention.

“I’ll make lunch when we get back. And don’t pull my hair.”

“I can't wait that long...I'm hungry now!”

“Alright, alright... we'll get something on the way.” He sounded annoyed but the thought of the three of them having lunch out together, like a little family, was appealing to him.

“Am I right though, Hidan?” Itachi asked, looping his arm around Kisame's and looking up at him, “Is that how it works?”

Hidan was quiet, “Not sure… maybe. I remember everything, but sometimes…” he squeezed his eyes shut for a moment, “I don’t know. I can’t explain it and it makes my head hurt to try.”

“It's alright, Hidan, don't give yourself a headache thinking about it too much. Itachi's probably right.” Kisame reached up to loosen Hidan’s hands from his hair, “Alright, this way!” Kisame turned a corner, “Let’s get lunch, my treat!” 

* * *

Hidan laid in bed between them, sound asleep and snoring softly while Kisame and Itachi read and talked quietly to each other, “It’s kinda nice, having him like this.” Kisame said, “I always wondered what having a kid or a baby brother would be like. I guess now I know.”

Itachi lowered his book, a small smile turning his lips up at the corners, “It’s not quite the same. He does remind me of Sasuke at times. Especially when we have to supervise him in the bath.”

“Oh?”

“Sasuke loved baths, like Hidan does. If he was in a rotten mood, my mother told me to put him in the bath. It almost always worked.”

Kisame chuckled softly, “So that’s why you make Hidan bathe sometimes twice a day.”

Itachi just nodded, “It can’t be easy for him being stuck like this.” 

“Pein said he expects Kakuzu and Konan back by morning. About time. They’ve been gone almost two months. Hidan will be glad to get back to normal.” Kisame pulled the blanket up, tucking it around Hidan’s small frame as Itachi watched.

“You’re going to miss this.” Itachi said.

“Won’t you?”

“Perhaps. I won’t miss having to his tantrums when he gets too hungry and tired and refuses to take a nap, or having to ask if he needs to use the toilet.” 

“I agree with you about that, but… this,” Kisame said, “I’ll miss this.” 

Itachi set his book down on the side table and settled into bed to sleep, “So will I. At the same time it will be nice to have our bed back, don’t you think?”

“Can’t argue with that.” Kisame leaned over to kiss Itachi on the forehead as Hidan rolled onto his side, mumbling something in his sleep and reaching out, not settling until he felt Itachi’s arm around him, and had a handful of Kisame’s shirt.

As they started to fall asleep, Kisame reached out to lace his fingers with Itachi’s, “Do you think he’ll find his way back in here with us once he’s his proper age?”

“I wouldn’t doubt it, Hidan seems to be more clingy than I imagined him to be.” Itachi yawned, “Goodnight, Kisa…” 

“‘Night.” 

* * *

Finally back, Kakuzu and Konan made their way through the base, stopping at Kisame and Itachi's open bedroom door, wondering if either were awake They stared in disbelief at Hidan in a footed onesie curled up between Kisame and Itachi. His tiny hand clutching tightly to Kisame’s shirt, while Itachi had an arm draped over him. All three of them sound asleep.

“Almost makes me not want to reverse the jutsu,” Konan said, keeping her voice down, “he’s actually pretty cute like this.”

Kakuzu nodded, “I almost agree with you.”

“But you want him back, I understand.” Konan put a hand on his shoulder, “It’s almost sunrise, you should wash up and get some rest, I’ll speak with Pein. That jutsu is not going to be easy to perform. We need to study it and determine which of us is best suited to use it. If it goes wrong, we may end up with another senior citizen.”

The thought of Hidan not returning to his actual age didn’t sit right with Kakuzu and he nodded. 

“Kuzu?” A small voice pulled him into the room and he watched Hidan sit up, rubbing his eyes in the dark.

“Hidan.”

“I missed you…” Hidan yawned, “You were gone so long.”

“I know. Go back to sleep.” Kakuzu pushed him back down, “What the hell are you wearing?” He was definitely going to tease him over wearing a footed shark onesie later but he also thought it was far too cute. 

“Shut up… it’s warm...” Hidan’s eyes closed as he snuggled up against Kisame’s chest, asleep again almost instantly.


End file.
